ARM: 7456/1: ptrace: provide separate functions for tracing syscall {entry,exit}
The syscall_trace on ARM takes a `why' parameter to indicate whether or
not we are entering or exiting a system call. This can be confusing for
people looking at the code since (a) it conflicts with the why register
alias in the entry assembly code and (b) it is not immediately clear
what it represents.
This patch splits up the syscall_trace function into separate wrappers
for syscall entry and exit, allowing the low-level syscall handling
code to branch to the appropriate function.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 10911c9..49d9f93 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -442,10 +442,9 @@
* context switches, and waiting for our parent to respond.
*/
__sys_trace:
- mov r2, scno
- add r1, sp, #S_OFF
- mov r0, #0 @ trace entry [IP = 0]
- bl syscall_trace
+ mov r1, scno
+ add r0, sp, #S_OFF
+ bl syscall_trace_enter
adr lr, BSYM(__sys_trace_return) @ return address
mov scno, r0 @ syscall number (possibly new)
@@ -457,10 +456,9 @@
__sys_trace_return:
str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
- mov r2, scno
- mov r1, sp
- mov r0, #1 @ trace exit [IP = 1]
- bl syscall_trace
+ mov r1, scno
+ mov r0, sp
+ bl syscall_trace_exit
b ret_slow_syscall
.align 5